Ketamine side effects

The uncompetitive NMDA receptor antagonist ketamine has been available for clinical use as an anaesthetic for 40 years (Domino et al. 1965). Ketamine is effective in various animal models of hyperalgesia and allodynia and has been reported to have antinociceptive effects in some of these models at doses devoid of obvious side-effects. Others, however, have reported that the effects of ketamine are only seen at doses producing ataxia (see Parsons 2001 for review). Ketamine reportedly inhibits the area of secondary hyperalgesia induced by chemical (Park et al. 1995) or thermal stimuli (Ilkjaer et al. 1996 Warncke et al. 1997) and inhibits temporal siunmation of repeated mechanical (Warncke et al. 1997) and electrical stimuli (Arendtnielsen et al. 1995 Andersen et al. 

Other reported side effects include vomiting, salivation, lacrimation, shivering, skin rash, and an interaction with thyroid preparations that may lead to hypertension and tachycardia. Ketamine also may raise intracranial pressure and elevate pulmonary vascular resistance, especially in children with trauma or congenital heart disease. Increases in intraocular pressure also may occur, and vigilance is required if ketamine is used in ocular surgery. 

Ketamine Non-competitive antagonist Beneficial with harmful side effects (Reeker et al., 2000)... 

The pharmacological effects of the R- and 5-enantiomers of ketamine have been compared in 11 subjects who received //-ketamine 0.5 mg and then 5-ketamine 0.15 mg, separated by 1 week (432). Before and after each drug administration they were subjected to a painful stimulus using a nerve stimulator applied to the right central incisor tooth. Pain suppression was equal with the two drugs. The subjects reported more unpleasant psychotomimetic effects with 5-ketamine and more pleasant effects with //-ketamine. Seven of eleven subjects preferred //-ketamine, while none preferred 5-ketamine. These results suggest that the neuropsychiatric effect of ketamine may be predominantly due to the 5-enantiomer, and that //-ketamine may be a better alternative. This study is in direct distinction to earlier work suggesting that //-ketamine is responsible for most of the undesirable neuropsychiatric side effects of ketamine. 

MEMANTINE ANAESTHETICS -GENERAL-KETAMINE t CNS side-effects Additive effects on NMDA receptors Avoid co-administration... 

Zsigmond EK, Kothary SP, Kumar SM, Kelsch RC. Counteraction of circulatory side effects of ketamine by pretreatment with diazepam. Clin Ther 1980 3(l) 28-32. 

Handa F, Tanaka M, Nishikawa T, Toyooka H. Effects of oral clonidine premedication on side effects of intravenous ketamine anesthesia a randomized, double-blind, placebo-controlled study. J Clin Anesth 2000 12(l) 19-24. 

The side-effects of reserpine include hypotension, bradycardia and increased gastrointestinal motility and diarrhea (Lloyd et al 1985), all resulting from decreased sympathetic tone and increased parasympathetic tone. The hypotensive effects of reserpine may take days to several weeks to occur but may persist for 1 to 6 weeks after the withdrawal of the dmg. Administration of induction agents, such as xylazine and ketamine, that produce hypotension may be fatal in horses treated with reserpine. 

Many of the side effects (e.g. granulocytopenia) encountered with racemic DOPA were not seen with levo-DOPA and therefore can be attributed to the (+)-enantiomer. For this reason the racemate is no longer given. Post-anesthesia reactions to the anesthetic and analgesic agent ketamine are overwhelmingly associated with the R(-) antipode. ... 

Known as special K, jet, green, and other names on the street, ketamine is sometimes injected, but can be evaporated to solid crystals, powdered, and smoked, snorted, or swallowed. Marijuana cigarettes are sometimes soaked in the ketamine solution, allowed to dry, and then smoked. Ketamine has become popular as a rave club drug. Side effects include signiflcant transient increases in blood pressure and heart rate, respiratory depression, airway obstruction, apnea, muscular hypertonia, psychomotor and psychotomimetic effects, and acute dystonic reactions. Following overdose, seizures, polyneuropathy, increased intracranial pressure, respiratory arrest, and cardiac arrest may occur. 

Ketamine is an arylcyclohexylamine, a congener of phencyclidine. It is supplied as a racemic mixture even though the S-isomer is more potent with fewer side effects. Although more lipophilic than thiopental, ketamine is water soluble and available as 10-, 50-, and 100-mg/mL solntions in sodium chloride plus the preservative benzethonium chloride. 

Ketamine (Ketalar, others) has unique properties that make it useful for anesthetizing patients at risk for hypotension and bronchospasm and for certain pediatric procednres. However, significant side effects limit its rontine nse. Ketamine rapidly produces a hypnotic state qnite distinct from that of other anesthetics. Patients have profonnd analgesia, nnresponsiveness to commands, and amnesia bnt may have their eyes open, move their limbs involnntarily, and breathe spontaneously. This cataleptic state has been termed dissociative anesthesia. 

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